Sierra International 18-2962 Marine Head Gasket for Johnson/Evinrude Outboard Motor Sierra Water Tube Guide Use with 18-3116 housing Sierra part number: 18-3109 Interchangeable with the following: GLM 12820, Mallory 9-45623, Mercruiser/Mercury 23-52928, 23-29804, 23-29804T Fit specific, check part numbers to ensure proper fit